<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }

        .box1{
            width: 100px;
            height: 100px;
            background-color: aquamarine;
            /* 脱离文档流，相对于有定位的父级元素进行定位，逐级寻找 */
            position: absolute;
            left: 50px;
            top: 50px;
        }
        .box2{
            width: 200px;
            height: 200px;
            background-color: orange;
        }

    </style>
</head>

<body>
    <div class="box1"></div>
    <div class="box2"></div>
</body>

</html>